Title: Yields of nuclear fragments in the interactions of carbon nuclei with a beryllium target at a projectile energy of 0.6 GeV per nucleon

Abstract

The yields of long-lived nuclear fragments at an angle of 3.5° that originate fromthe fragmentation of carbon ions with an energy of T{sub 0} = 0.6 GeV per nucleon on a berylliumtarget were measured in the FRAGMexperiment at the ITEP TWA heavy-ion accelerator. The momentum spectra of these fragments cover both the fragmentation-maximum region and the cumulative region. The respective differential cross sections change by about five orders of magnitude. The momentum distributions of fragments in the laboratory frame and their kinetic-energy distributions in the rest frame of the fragmenting nucleus are used to test the predictions of four models of ion–ion interactions: BC, INCL++, LAQGSM03.03, and QMD.

@article{osti_22612620,
title = {Yields of nuclear fragments in the interactions of carbon nuclei with a beryllium target at a projectile energy of 0.6 GeV per nucleon},
author = {Abramov, B. M. and Alexeev, P. N. and Borodin, Yu. A. and Bulychjov, S. A. and Gudima, K. K. and Dukhovskoy, I. A. and Krutenkova, A. P., E-mail: anna.krutenkova@itep.ru and Kulikov, V. V. and Martemianov, M. A. and Matsyuk, M. A. and Mashnik, S. G. and Turdakina, E. N. and Khanov, A. I.},
abstractNote = {The yields of long-lived nuclear fragments at an angle of 3.5° that originate fromthe fragmentation of carbon ions with an energy of T{sub 0} = 0.6 GeV per nucleon on a berylliumtarget were measured in the FRAGMexperiment at the ITEP TWA heavy-ion accelerator. The momentum spectra of these fragments cover both the fragmentation-maximum region and the cumulative region. The respective differential cross sections change by about five orders of magnitude. The momentum distributions of fragments in the laboratory frame and their kinetic-energy distributions in the rest frame of the fragmenting nucleus are used to test the predictions of four models of ion–ion interactions: BC, INCL++, LAQGSM03.03, and QMD.},
doi = {10.1134/S1063778816050033},
journal = {Physics of Atomic Nuclei},
number = 5,
volume = 79,
place = {United States},
year = 2016,
month = 9
}

Intra-and intergroup azimuthal correlations of projectile and target fragments are found in collisions between gold and emulsion nuclei. The statistical significance of these correlations is high. The methodological distortions associated with the measurement errors are investigated in detail and are taken into account.

Intra-and intergroup azimuthal correlations of projectile and target fragments are found in collisions between gold and emulsion nuclei. The statistical significance of these correlations is high. The methodological distortions associated with the measurement errors are investigated in detail and are taken into account.

Nuclear emulsions have been used to study the dependence of the characteristics of fast fragments on the masses and impact parameter of the interacting nuclei in the range of incident-particle masses from the proton up to neon. A substantial hardening of the energy spectra of the recoil nucleons from the target nucleus is observed with increase of the number of interacting nucleons in an individual event. A comprehensive comparison is made with the results of calculations according to the cascade-evaporative model.

Two independent emulsion experiments using Bevalac beams of /sup 16/O and /sup 56/Fe at approx.2 GeV/ nucleon find with >99.7% confidence that the reaction mean-free paths of projectile fragments, 3< or =Z< or =26, are shorter for a few centimeters after their emission than at larger distances, or than predicted from experiments on beam nuclei. This effect, which is enhanced in later generations of fragments, can be interpreted by the relatively rare occurrence of fragments that interact with an unexpectedly large cross section.